The present invention generally relates to credit card reading systems, and more particularly to a credit card reader for reading binary coded data recorded on credit cards and the like independently of the speed at which the credit card is moved relative to the readout means.
There has recently been developed numerous electronic systems for reading price tags, credit cards and similar documents. Typically, conventional magnetic heads are used which are moved relative to the item from which recorded data is to be extracted. A major problem in the known systems has been the great dependency of the systems upon the variations in distance or speed of movement of magnetic reading heads relative to the material being read. For example, such variations may produce distortions, low amplitude outputs, or otherwise provide unsatisfactory or incorrect output data.
One approach recently has been to provide precise mechanical designs which insure that tape, for example, bearing the recorded data, moves past the readout head at a constant speed. In addition to the great expense involved in designing and manufacturing such a mechanical system, the complexity of the same lends itself to frequent malfunction and difficulty in making repairs to the same.
One approach to remove the emphasis from constant speed reading systems has been to place more reliance on electronic circuitry which compensates for the irregularities caused by the mechanical speed variations. These electronic circuits are also complex in construction and generally suffer similar disadvantages above described.
A more recent approach has been the utilization of Hall-effect readout heads which effectively eliminate the need for much of the electronic circuitry heretofore required. The use of Hall-effect heads has also considerably reduced the requirement of mechanical complexity of the system. See, for example, "Hall-Effect Magnetic Sensor Reads Data At Any Speed", Electronics, February 1, 1973; and "New Hall-Effect Heads Hold Big Promise", Japan Electronic Engineering, September, 1972.
While the Hall-effect magnetic sensors have eliminated some of the problems inherent in prior art systems, they themselves suffer from temperature instability problems. Consequently, some of the circuit complexity eliminated by the utilization of Hall-effect readout heads is reintroduced in the form of temperature stabilizing and compensating networks which prevent erroneous output data readouts.
Accordingly, the prior art devices have still not provided a simple, inexpensive mode of reading out data from credit cards, for example. Such a device is, very desirable, however, for use in equipment such as POS (Point of Sale) terminals. With such equipment, where sales personnel operate the same, it is necessary that the equipment furnish accurate data irrespective of the manner in which the sales personnel manually operate the equipment. More particularly, correct output readings are required independent of the speed of movement of the credit card relative to the readout device.